Alder Home Security will not update system to work properly, claim I need to keep paying. Raceland Kentucky

I changed my internet provider and the system needs upgrade to work properly. I try to schedule this, get an appointment with an all day time frame, and the technician no longer works for them or they simply don't show up. I call and all they want to do is reschedule, tell me a supervisor would do the same thing.  Won't give me a phone number for anyone in the company that isn't in a call center, tell me I have to keep paying them regardless, can't find a physical mailing address.  I've been paying for a useless system for 6 months and I want out of this NOW.